A multiplicity of different types of skylights have been developed over the years. Basically they are designed for providing access of light and air through a roof structure. They are mounted within an opening in a building structure such as a roof in a variety of different ways. The overall objective of the mounting operation is to maintain a sealed interengagement to prevent leakage while permitting an unobstructed passageway for vision and light.
Various designs include means for opening and closing the skylight to provide ventilation capability as well as an access means for the passage of light. The skylight dome structure through which the light passes is formed of a transparent or translucent material. Certain plastic such as acrylics, and glass materials are commonly used for this purpose.
Of course, with use of materials designed to permit the passage of sunlight therethrough, there is often concern over the amount of heat introduced by the sunlight into the interior of the building. Also, at times it is necessary to reduce the amount of light passing through the skylight. This concern of the amount of heat and light permitted to pass through the skylight is normally not controllable by the skylight structure alone. The intensity of the heat and light to which the skylight is subjected is also variable and depends on natural conditions such as the angle of the sun with respect to the skylight and whether or not it is a partly cloudy or cloudy day.
Accordingly, there is clearly a need for improved ways in which to control the amount of heat and light passing through the skylight and into the enclosure covered by the roof structure.
Also, it is sometimes advantageous to partially or fully obscure the visual passageway through the skylight, such as for security or privacy purposes for example.
Examples of patents showing skylight structures in which improvement is desirable in order to further control the amount of heat and light passing within the structure or the size of the visual passageway therethrough include U.S. Pat. Nos. 2,875,710, 3,090,613, 4,408,422, 4,441,284 and 4,594,821. These patents show the sequence of developments in recent years in regard to skylight design and show structures which are readily adaptable to the concept of the present invention and therefore, the content of each of these patents is incorporated herein by reference.
It should also be kept in mind that in providing a structure for controlling the visual passageway through a skylight, that structure should have certain features. It should be concealed wherever possible so that the aesthetic appearance of the skylight assembly and the visual passageway is not unduly detracted from. It should also be mounted on the interior wherever possible to provide advantages in manufacture, installation and maintenance. Furthermore, in those embodiments where an actuator mechanism is employed for shifting the structure to partially or completely obscure the skylight opening, and the actuator includes a cord, it is desirable to provide a means for affixing a cord to maintain the structure in position, to prevent accidental slippage of the cord, and to prevent the cord from shifting too quickly which could cause damage or at least distracting movement of the structure with respect to the skylight.